The present invention relates generally to apparatus for forming joints between lengths of tubular stock or the like and, more particularly, to the use of an eyebolt and a crossbolt to join lengths of tubular stock together in a rigid joint.
It is well known in the art to join tubular elements such as used for hand rails, fences, furniture and the like using commonly available connector elements or, in the case of metal components, by welding. Connector elements should be inexpensive to manufacture and simple to assemble. Further, the connectors, when assembled, should form a mechanically strong and rigid joint between the tubular elements.
Australian Pat. No. 274,749 entitled "An Improved Strainer Post" issued to Robert Jordan Martin and Barbara Martin and published on Jan. 20, 1966 discloses apparatus for connecting sections of tubular pipe together comprising an eyebolt passing through a first pipe and a crossbolt through the end of a second pipe such that the crossbolt engages the eye and attaches the second pipe to the eyebolt. The eyebolt is inserted through the first pipe with the eye portion projecting on one side and the threaded portion projecting on the opposite side of the pipe. The open end of the second pipe is positioned over the projecting eye and the crossbolt is inserted through apertures in the second pipe near the open end engaging the eye and attaching the second pipe to the eye. A nut on the threaded portion of the eyebolt is then tightened up to draw the end of the second pipe firmly against the side of the first pipe to hold it in place, or, alternatively, the nut may be left relatively loose to allow the second pipe to pivot about an axis extending through the eye of the eyebolt. The coupling method disclosed by Martin et al, while being satisfactory for systems under tension, does not provide a joint having sufficient mechanical strength or rigidity for some applications. U.S. Pat. Nos. 3,471,182 and 3,851,981 provide additional examples of prior art connector elements.